Traceroute

Traceroute (or tracert on Windows) reveals the sequence of routers a packet passes through on its way to a destination, along with the latency to each hop. It works by sending packets with an increasing time-to-live value; each router that discards an expired packet reveals itself, building the path one hop at a time. Reading it top to bottom, you can often spot exactly where delay spikes or packets start disappearing — a congested link, a long-haul jump between cities or an unresponsive router shown as asterisks.

Traceroute is invaluable for understanding why a route is slow and for confirming that traffic really leaves through the exit you expect. When you connect through the s4m VPN or a proxy, a traceroute from an outside observer to you stops at the exit rather than reaching your real origin, which is exactly the point — your true IP stays behind the hop. Note that some routers do not answer, appearing as timeouts even on a healthy path, so a few asterisks in the middle of an otherwise complete trace are usually nothing to worry about.

Read a traceroute from the top down and look for the hop where latency first jumps or replies start disappearing — that is usually where the problem lives, often a long-haul link between cities. A few asterisks mid-path are normal, since some routers simply do not answer. Running a trace both directly and through a VPN or proxy also confirms that your traffic really leaves via the exit you expect rather than your own connection.